tbuckley/cabot-search huggingface dataset:
Abstract GS.03: Functional Role Of Placental Senescence In Peripartum Cardiomyopathy
Authors: Claire Castro, Andy Yu, Sarosh Rana, Sajid Sahul, Kathryn J Gray, Michael C Honigberg, Melanie Ricke-Hoch, Peng Xia, Zeina R. Al Sayed, Carmen Diaz Verdugo, James Kirkland, Patrick T Ellinor, Ananth A Karumanchi, Zoltan Arany, Denise Hilfiker-Kleiner, Anthony Rosenzweig, Jason D Roh
Journal: Circulation Research (2023)

Introduction: Peripartum cardiomyopathy (PPCM) and preeclampsia (PEC) are leading causes of maternal mortality with limited therapies. Circulating factors in late pregnancy contribute to cardiac dysfunction in PPCM and PEC. We recently identified senescence-associated secretory proteins (SASP), markers of biological aging, as the most highly upregulated circulating proteins in PPCM and PEC. The mechanisms driving this paradoxical aging pathophysiology in these pregnancy-induced heart failure (HF) syndromes are unknown. Hypothesis: The placenta becomes markedly senescent by term. We hypothesized that 1) amplified placental senescence causes the increase in circulating SASP in PPCM and PEC, and 2) attenuating placental senescence might improve cardiac function in PPCM. Methods: We performed comprehensive senescence assessments in placental samples from women with preeclampsia vs . matched pregnant controls. We assessed the effects of placental senescence in human iPSC-derived cardiomyocytes (iPSC-CM) and the PGC1α-KO PPCM murine model. Results: Placentas from PEC women displayed multiple markers of amplified senescence, including increased p16 and p21 expression (2 &amp; 4 fold, p&lt;0.03), decreased DNA methylation (-1.7 fold, p&lt;0.04), and increased overall SASP expression (2 fold; p&lt;0.001). In iPSC-CM, PEC plasma induced pathologic gene expression profiles (Nppa, Nppb, Myh7) and increased Activin-A signaling (Fstl3, Serpine1, Ccn2), a key SASP factor that contributes to cardiac dysfunction in PEC and PPCM. The senolytic Fisetin attenuated placental senescence in pregnant PGC1α-KO mice, reducing placental p16 and p21 expression (-2 &amp; -3 fold, p&lt;0.01) and Activin-A levels (-2 fold, p&lt;0.03). Compared to vehicle-treated pregnant PGC1α-KO mice, Fisetin-treated animals had 35% higher left ventricular fractional shortening (31% vs . 42%; p&lt;0.001), along with reductions in cardiac Nppa expression and Activin signaling. No changes in cardiac senescence or adverse effects on fetal development were observed with Fisetin. Conclusion: We identify amplified placental senescence as part of the core pathobiology underlying PPCM and PEC, and present proof-of-concept evidence for senolytic therapeutic approaches in pregnancy-induced HF.
Abstract P3092: Histone Deacetylase 6 Inhibitor Suppresses The Inflammation Through MIR17HG In LPS-Induced Macrophages
Authors: Selene Perales, Vinoth Sigamani, Sheeja Rajasingh, Rajasingh Johnson
Journal: Circulation Research (2023)

Background: Long non-coding RNAs (lncRNAs) have been linked to a wide range of pathologic diseases despite having a limited capacity for protein coding. MIR17HG is the host gene for the miR17-92a-1 cluster, a group of six microRNAs involved in several cellular functions. Dysregulation of MIR17HG has been associated with multiple diseases such as Feingold Syndrome, osteoarthritis, Parkinson’s disease, and cancer. Treatment with histone deacetylase-6 inhibitor (Tubastatin A -TBA) reduces inflammatory response on macrophages after LPS challenge. Here, we analyze the role of MIR17HG as an epigenetic regulator of inflammation in LPS-induced THP1 cells. Hypothesis: We hypothesize that TBA suppresses the effect of MIR17HG and promotes protection in macrophages under LPS-induced inflammation. Methods and Results: To elucidate potential lncRNAs of interest during macrophage inflammatory response, we treated macrophages with LPS (1 μg/mL) and TBA (2.5 μM) for 1hr and performed RNA sequencing. We selected MIR17HG for further investigation based on the sequencing data (Fig. A) and bioinformatic analysis. The expression of MIR17HG in LPS and TBA treatment conditions was validated by qRT-PCR. MIR17HG expression was significantly higher in LPS and treatment with TBA suppressed the LPS-stimulated MIR17HG expression (Fig. B, C) . We also observed the IL1β behaved in a similar manner (Fig. D) . Further overexpression and knockdown experiments will be performed to identify the link between MIR17HG and ILβ. Conclusion: We report for the first time that MIR17HG is an important mediator of the pro-inflammatory response of macrophages.
Abstract P3185: ATP Citrate Lyase Regulates Cardiomyocyte Function By Controlling Mitochondrial Reductive Stress
Authors: Mariam Meddeb, Navid Koleini, Seungho Jun, Mohammad Keykhaei, Farnaz Farshidfar, Liang Zhao, Abigail Mulligan, Seoyoung Kwon, Brian Lin, Gizem Keceli, Kavita Sharma, Mark J Ranek, Nazareno Paolocci, Erika L Pearce, David A Kass
Journal: Circulation Research (2023)

ATP citrate lyase (ACLY) is a cytosolic enzyme that converts citrate transported from the mitochondria into oxaloacetate and acetyl-CoA. It was recently reported to support a non-canonical TCA cycle, which is particularly important in immature and proliferating cells. Cardiomyocytes are both mature and non-proliferating and the role of ACLY in such cells is unknown. Using uniformly labeled C 13 glucose, we found that inhibiting ACLY using highly specific BMS-303141 (ACLY-I) significantly elevated M2 malate/M2 citrate ratio in adult cardiomyocytes in 1 hour, indicating their engagement in a non-canonical TCA cycle. In isolated hearts (Langendorff), we found both dP/dt max and dP/dt min markedly depressed after 40 minutes of ACLY-I. Isolated adult myocytes exposed to 1 hour of ACLY-I had depressed sarcomere shortening and prolonged relaxation. Reactive oxygen species was unchanged. BMS303141 at &gt;10 μM was cardiotoxic while concentrations up to 50μM are not toxic in cardiac fibroblasts or hepatocytes. Untargeted metabolomics from ACLY-I treated hearts found significant decreases in TCA cycle intermediates citrate and α-ketoglutarate, accompanied by reduction in ATP production despite accumulation of NADH. The NAD/NADH ratio was reduced after 1-hr ACLY-I in cardiomyocytes, supporting its induction of reductive stress. Consistent with this, lactate was increased perhaps as a mechanism to oxidize NADH and alleviate reductive stress. These results have translational importance, as we find in human heart failure biopsies that ACLY is significantly downregulated at both transcript and protein levels. This finding is inversely related to body mass index, raising the hypothesis that exposure to high fat diet may reduce ACLY levels. This was tested in adult cardiomyocytes isolated from hearts 4 weeks after transaortic constriction and then treated with palmitate and oleate. ACLY mRNA declined post fatty acid treatment and paralleled a decline in ACLY promoter activity. These results identify a critical role of ACLY in normal myocyte NAD/NADH balance and mitochondrial function. ACLY reduction in heart failure particularly with obesity (e.g. heart failure with preserved ejection fraction) suggests a potentially new metabolic therapeutic target.
Abstract P2116: Role Of Cardiomyocyte Specific Pellino-1, An E3 Ligase On Therapeutic Angiogenesis And Attenuation Of Ventricular Remodeling In A Murine Myocardial Infarction Model
Authors: Andrew Kemerley, Seetur R Pradeep, Mahesh Thirunavukkarasu, Diego Accorsi, Santosh Swaminathan, Sue Ting Lim, Jennifer Hubbard, Siu-Pok Yee, Nilanjana Maulik
Journal: Circulation Research (2023)

Ubiquitination plays a vital role in our system in controlling vascular inflammation, cellular protein quality control, and minimizing misfolded protein toxicity. Pellino1 (Peli1), a type of E3 ubiquitin ligase, has emerged as a critical regulator of the innate immune response; however, its role in the repair and regeneration of ischemic myocardium remains to be elucidated. Materials: Cardiomyocytes isolated from Wild type (WT), cardiomyocyte-specific Peli1 overexpressed (AMPEL1Tg/+), and cardiomyocyte specific Peli1 knockout (CP1KO) mice were cultured and exposed to 6 h hypoxia, and the conditioned media (CM) collected. CMs were used to treat mouse cardiac endothelial cells (MCECs) followed by H2O2 treatment. Cells were used for Western blot, Flow cytometry, and scratch analyses. For in vivo myocardial infarction (MI) model, animals were exposed to left anterior descending artery (LAD) ligation. Animals were divided into (a) WT, (b) AMPEL1Tg/+(c) CP1KO and subjected to sham (S) and MI. Results: In vitro study documented faster wound closure and increased expression of angiogenic factors (pFlk-1, Ang-1 and VEGF) with MCECs treated with CM obtained from AMPEL1 compared to the other CM obtained from CP1KO and WT. There was no change in cardiac functions between Sham groups. AMPEL1Tg/+ MI group, showed preserved systolic functions, represented by both EF [n=12-14, p&lt;0.0001] and FS [n=12-14, p&lt;0.0001] compared to WTMI. However, CP1KO MI showed loss of systolic function, as represented by EF [n=13, p=0.03] and FS [n=13, p=0.03] compared to WTMI. The extent of fibrosis is also reduced in AMPEL1MI [n=5, p=0.0031], but increased in CP1KOMI [n=6-7, p&lt;0.0001] compared to WTMI. Capillary n=4-5, p=0.0010] and arteriolar density [n=5, p=0.0005] were increased in AMPEL1MI but reduced in CP1KOMI [n=6, p&lt;0.0001]; [n=5-7, p=0.02] compared to WTMI. Western blot analysis documented increased survival and angiogenic factors (pAKT, VEGF, and Bcl2) in AMPEL1MI compared to CP1KOMI and WTMI. Conclusion: Our study uncovers the role of cardiomyocyte-specific Peli1 as a regulator of repair and regeneration of ischemic myocardium, as evidenced by preserved cardiac function, increased expression of angiogenic factors, and reduction of apoptotic markers in the MI model.
Abstract P2079: Heart Rate Variability And Chronotropic Incompetence As Prognostic Markers In A Preclinical Model Of HFpEF
Authors: Patricia Perez-Bonilla, Xian Chen, Brianna LaViolette, Dinesh Hirenallur-Shanthappa
Journal: Circulation Research (2023)

The prevalence of heart failure with preserved ejection fraction (HFpEF) in developed countries is increasing alarmingly. This is in part due to an increase in comorbid diseases (obesity, diabetes, hypertension), and risk factors (age, stress, and low physical activity). HFpEF patients often present with chronotropic incompetence (CI) and impaired heart rate variability (HRV), and both CI and decreased HRV are used as prognostic markers of heart disease and sudden cardiac death in clinical studies. In preclinical HFpEF models, however, CI and HRV are not commonly evaluated, and the efficacy of novel compounds is determined primarily through echocardiography results. Thus, there is a need to align efficacy readouts to enhance the translatability of novel compounds from preclinical to clinical stages. Here we sought to determine the utility of CI and HRV in preclinical HFpEF studies in a novel 2-hit HFpEF model; the metabolic syndrome non-alcoholic steatohepatitis mouse with AAV overexpression of renin (MS-NASH+Renin). To collect continuous and conscious electrocardiogram and blood pressure data, C57BL/6 (n=10) and MS-NASH (formerly FATZO, n=32) male mice were implanted with radiotelemeters at 20 weeks and iv injected with either AAV-Vector or AAV-Renin. To assess disease burden, CI and HRV, we acquired and analyzed body weight, electrocardiography, peak VO2, exercise HR, and echocardiography data once a month for 5 months. We found that MS-NASH mice have increased body weight regardless of treatment, and that renin treatment increased blood pressure for both C57BL/6 and MS-NASH mice. Peak VO2, time to exhaustion, distance traveled, and maximum and recovery HR are significantly decreased in MS-NASH mice, indicating CI. HRV is also significantly decreased in MS-NASH mice when compared to C57BL/6. Interestingly, renin treatment did not further decrease treadmill performance or HRV for MS-NASH mice. However, MS-NASH+Renin mice did have decreased functional capacity with preserved ejection fraction and altered heart structure. These results suggest that MS-NASH+Renin is a model for HFpEF, and that CI and HRV are translatable markers for HFpEF. In the future, we will evaluate the use of CI and HRV in preclinical HFpEF drug development studies.
Abstract P3177: Complex I-induced Protein Turnover, A Novel Mitochondrial Protein Quality Regulation Clipt Goes Beyond The Mitochondrial Calcium Uniporter
Authors: Sandra Lee, David Eberdhardt, Enrique Balderas, Anthony Balynas, Xue Yin, Dipayan Chaudhuri
Journal: Circulation Research (2023)

In the setting of mitochondrial disease, patients with cardiac involvement have a nearly threefold increased mortality. Yet, patients often survive months to years suggesting that in cardiomyocytes, there is a compensatory mechanism that maintains energy synthesis despite defective mitochondria. We have recently shown that enhanced activity of the mitochondrial Calcium (Ca 2+ ) uniporter channel preserves energetic homeostasis in mitochondrial cardiomyopathies. Here, we describe a novel mechanism responsible for this enhancement. During normal physiology, interaction between the uniporter and Complex I of the electron transport chain promotes its degradation. However, upon Complex I dysfunction, loss of this interaction results in increased functional channels. We termed this form of mitochondrial protein regulation, Complex I-Induced protein turnover (CLIPT). We hypothesize that CLIPT is not unique to the uniporter. To identify other candidates subject to CLIPT, we performed a pulse-chase screen using TurboID, a biotin-ligase proximity labeling tool. HEK cells expressing a mitochondrial TurboID were grown with or without Complex I inhibitors. Following a pulse-chase with biotin, proteins were purified with streptavidin and identified through mass spectrometry. Of these proteins, whose lifetimes increased after Complex I inhibition, Peroxiredoxin-3 (PRDX-3) is a mitochondrial antioxidant shown to provide protection against cell death and in myocardial infarction. Using heterologous expression in c2c12 cells, inhibition of Complex I prolongs PRDX-3 lifetime. Thus, our data suggests that CLIPT can affect mitochondrial proteins beyond the uniporter.
Abstract P3063: Selective Release Of Mitochondrial Dna After Brief Myocardial Ischemia
Authors: Daniel M Cucinotta, Tyler Rolland, Sumbule Zahra, Brian R Weil
Journal: Circulation Research (2023)

Objective: Mitochondrial DNA (mtDNA) is one of several pro-inflammatory damage-associated molecular patterns released from necrotic myocytes during myocardial infarction (MI). Based on our recent observation of a ~50-fold rise in circulating mtDNA after brief whole-body ischemia in a porcine model of cardiac arrest without ongoing MI, we hypothesized that ischemia-induced mtDNA release can occur in the absence of necrosis. Accordingly, we measured circulating mtDNA levels before and after localized myocardial ischemia of insufficient duration to produce myocyte necrosis in swine. Methods: Swine (n=6) were subjected to a 10-minute occlusion of the left anterior descending (LAD) coronary artery based on prior evidence that this duration of ischemia elicits myocardial injury without necrosis. Peripheral venous and coronary sinus (CS) blood samples collected at baseline (BL) as well as 1-hour and 24-hours after reperfusion were analyzed via qPCR to quantify mtDNA and nuclear DNA (nucDNA) release. Results were compared to a separate group of swine (n=6) subjected to a 75-minute LAD occlusion to produce MI. Results: Prolonged ischemia led to a significant rise in CS levels of mtDNA (6.2 ± 3.6-fold vs. BL; p&lt;0.05) and nucDNA (5.4 ± 2.0-fold vs. BL; p&lt;0.05) 1 hour after reperfusion, consistent with rapid non-selective DNA release after myocyte necrosis. In contrast, brief ischemia was associated with detectable elevations in CS mtDNA (4.6 ± 1.4-fold vs. BL; p&lt;0.05) but not nucDNA (2.1 ± 0.5-fold vs. BL; p=0.35) at this timepoint. However, the magnitude of DNA release after brief or prolonged ischemia was not sufficient to increase circulating mtDNA or nucDNA, as peripheral venous levels of mtDNA and nucDNA did not differ from BL at 1-hour or 24-hours post-reperfusion in either group. Conclusion: Brief myocardial ischemia is associated with selective release of mtDNA into circulation, providing a potential mechanism by which immune activation may occur after myocardial injury even when myocyte necrosis is absent. The magnitude of mtDNA release after brief myocardial ischemia is ~10-fold lower than that detected in peripheral blood after resuscitation from cardiac arrest, suggesting that mtDNA is released from other organs after brief whole-body ischemia.
Abstract P2074: Site-specific Phosphorylation Of Vinculin Regulates N-cadherin Junction Assembly
Authors: Glenn Radice, Xiaofei Li, Rainy Wortelboer, Callie McLain
Journal: Circulation Research (2023)

Introduction: During physiological and pathological growth, cardiomyocytes adapt and remodel in response to changes in mechanical load. The cytoskeleton plays a central role in tissue remodeling as it both senses mechanical stress and mediates structural remodeling which affects the functional response within the cardiomyocyte. Abl kinase-dependent vinculin (VCL) phosphorylation at tyrosine (Y) residue 822 (pVCL-Y822) has been implicated in force-induced cytoskeletal remodeling and adhesion strengthening at cadherin junctions. However, the functional significance of VCL phosphorylation in the working myocardium remains unknown. Objective: To determine the role of vinculin-mediated mechanotransduction in cardiac development, homeostasis, and disease. Methods and Results: Using a phospho-specific antibody, we found that pVCL-Y822 correlates with dynamic junction remodeling in embryonic cardiomyocytes which declines in the postnatal heart when N-cadherin junctions assemble at the intercalated disc. Notably, pVCL-Y822 is upregulated in border zone cardiomyocytes following myocardial infarction. To investigate VCL-mediated mechanotransduction in the heart, CRISPR-mediated genome editing was used to mutate the tyrosine at position 822 to a non-phosphorylatable phenylalanine (F) in the mouse Vcl gene. Vcl Y822F mice were born in the expected Mendelian frequency and are viable. Blocking VCL phosphorylation causes a preferential reduction of mutant VCL protein at the myocyte termini together with the N-cadherin-catenin adhesion complex. Whereas, α5/β1 integrin and fibronectin are both increased along the lateral border of the Vcl Y822F postnatal cardiomyocytes. Vcl Y822F mice exhibit reduced cardiac function with age; however, cardiac remodeling is attenuated in the mutant hearts. Conclusion: This novel animal model demonstrates how blocking vinculin Y822 phosphorylation affects the balance between cadherin adhesions and integrin adhesions and thereby highlights the importance of understanding the crosstalk between the two adhesion systems and its implications for disease pathogenesis.
Abstract P3006: Inhibition Of Tnfα Signaling Delay CAVD Progression In Mice
Authors: Zar Chi Thent, Sonia Benkaci, Bingruo Wu, Jonathan T Butcher, Bin Zhou
Journal: Circulation Research (2023)

Background: Inflammation is a prominent feature of calcific aortic valve disease (CAVD), a leading cause of aortic stenosis. Inflammation can activate surface valvular endothelial cells (VEC) to produce pathogenic signaling such as Tumor Necrosis Factor-alpha (TNFα), to valvular interstitial cells (VIC) in aortic valve leaflets, leading to pathological valve remodeling through increased extracellular matrix synthesis, calcium deposition, and cell death which underlies CAVD. Thus, TNFα inflammatory signaling maybe a major candidate therapeutic target for alleviating CAVD progression. Hypothesis: We hypothesized that inhibition of TNFα signaling may delay CAVD progression. Results: We compared CAVD progression in a mouse model of CAVD with deletion of Ldlr, low-density lipoprotein receptor, and fed with standard or high fat diet. We inhibited the TNFα inflammatory signaling in this CAVD model by crossing the Ldlr -/- mice with the Tnfr1 and Tnfr2 double null mice. The aortic valve functions were measured by echocardiogram and the results showed that aortic valve velocity was significantly decreased in the triple null ( Ldlr -/- ;Tnfr1 -/- ;Tnfr2 -/- ) group compared to the Ldlr -/- group, both fed with high fat diet. Contractile function (systole to diastole ratio) at the aortic root was significantly increased in the triple null group. Aortic valve histopathology was examined by various staining methods. In the triple null mice, Hematoxylin and Eosin (H&amp;E) showed significantly reduced the thickness of aortic valve leaflets; Masson’s Trichrome, Picrosirius Red, and Rusell-Movat staining revealed significantly reduced fibrosis and collagen deposition, and Von Kossa and Alizarin Red staining showed significantly decreased calcium deposition. Furthermore, immunofluorescence staining demonstrated significantly decreased DNA damage and cell death, as well as cell proliferation in aortic valve leaflets of the triple null mice. Conclusion: Our findings demonstrate a promising role of inhibiting TNFα signaling in slowing CAVD progression in mice, suggesting pharmacological or immunological inhibition of TNFα signaling as a non-invasive therapeutic option to treat CAVD patients.
Abstract P3188: Establishing The Mitochondrial Citrate Transporter As A Regulator Of Cardiac Morphogenesis
Authors: Chiemela Ohanele*, Jessica Peoples*, Anja Karlstaedt, Ashley Gayle, Nasab Ghazal, Fateemaa Sohani, Milton E Brown, Michael Davis, Victor Faundez, Jennifer Q Kwong
Journal: Circulation Research (2023)

Congenital heart disease (CHD) results from structural and functional defects of the heart that arise during embryonic development. CHD represents the most common type of birth defect and in the United States alone, affects ~1% of births per year. One common genetic cause of CHD is 22q11.2 deletion syndrome (22q11.2DS), where ~75% of 22q11.2DS patients present with CHD. SLC25A1 , which is found within the 22q11.2DS critical deletion region, encodes for the mitochondrial citrate carrier, a solute transporter localized to the inner mitochondrial membrane. In developing a knockout mouse model to study the in vivo functions of SLC25A1, we uncovered an unexpected perinatal-lethal phenotype that suggests roles for SLC25A1 in heart development. Hearts from Slc25a1 knockout embryos display a striking array of cardiac malformations including persistence of an expanded zone of trabeculated myocardium, reduced compact myocardium, and ventricular septal defects. Analysis of mitochondrial structure and function reveal that loss of Slc25a1 causes mitochondrial ultrastructural and functional defects. Lastly, transcriptomics analyses of metabolism-related genes revealed that Slc25a1 deletion causes widespread alterations in metabolic gene expression in a dosage-dependent manner. Our results highlight a novel role for SLC25A1 in cardiac morphogenesis and the transcriptional control of metabolic networks in the developing heart and point to a new role for SLC25A1 in the metabolic maturation of the developing myocardium.